1. Field of the Invention
The invention relates to a method of reconstructing a high resolution image by tomodensitometry with the purpose of improving the quality of the reconstructed image without burdening the technological structure of the means for measuring the penetrating radiation absorption and without substantially modifying the data acquisition procedure.
2. Description of the Prior Art
So called "third generation" tomodensitometers are essentially formed from a source of penetrating radiation (X rays) emitting a flat fan-shaped beam, a curved row of detectors placed opposite this source so as to measure the unabsorbed fraction of the radiation in the plane of the section of which an image is to be formed, means for rotating the source and the detectors in the plane of this section and a processor for processing the data supplied by the detectors and for reconstructing an image from this data. The spatial resolution of the reconstructed image depends more particularly on the number of detectors covering the fan shape of the X ray beam. For a given beam aperture, the higher the number of detectors the better the spatial resolution. However, the multi-detector assembly is one of the most expensive parts of the tomodensitometer and one of those which is the most difficult to produce with good reliability. Consequently, the increase in the number of detectors on a given sector corresponding to the fan shape, comes up against technological limits.
One of the aims of the invention is to substantially improve the quality of the image without modifying the technological structure of the source-detectors assembly and without substantially modifying the data acquisition procedure properly speaking.
Another aim of the invention is also to reduce the cost of construction of a tomodensitometer having spatial resolution comparable to that of existing tomodensitometers, this reduction in cost being obtained by using a multidetector assembly comprising only half the number of detectors of exising machines.